Low Cost 150 Watt Amplifier Circuit

In this project, we’re building a simple 150 watt amplifier circuit.

Description

This is the cheapest 150 Watt amplifier circuit you can make,I think.Based on two Darlington power transistors TIP 142 and TIP 147 ,this circuit can deliver a blasting 150 W Rms to a 4 Ohm speaker.Enough for you to get rocked?;then try out this.

TIP 147 and 142 are complementary Darlington pair transistors which can handle 5 A current and 100V ,famous for their ruggedness. Here two BC 558 transistors Q5 and Q4 are wired as pre amplifier and TIP 142 ,TIP 147 together with TIP41 (Q1,Q2,Q3) is used for driving the speaker.This circuit is designed so rugged that this can be assembled even on a perf board or even by pin to pin soldering.The circuit can be powered from a +/-45V, 5A dual power supply.You must try this circuit.Its working great!

The preamplifier section of this circuit is based around Q4 and Q5 which forms a differential amplifier. The use of a differential amplifier in the input stage reduces noise and also provides a means for applying negative feedback. Thus overall performance of the amplifier is improved. Input signal is applied to the base of Q5 through the DC decoupling capacitor C2. Feedback voltage is applied to the base of Q4 from the junction of 0.33 ohm resistors through the 22K resistor. A complementary Class AB push-pull stage is built around the transistors Q1 and Q2 for driving the loud speaker. Diodes D1 and D2 biases the complementary pair and ensures Class AB operation. Transistor Q3 drives the push-pull pair and its base is directly coupled to the collector of Q5.

Circuit Diagram & Parts List .

150 watt amplifier circuit diagram

PCB’s for this project can be ordered through PCBWay. We shall upload a sample PCB file (for download) shortly.

Notes.

Remember TIP 142 and 147 are Darlington pairs .They are shown as conventional transistors in figure for ease.So don’t get confused.Even though each of them have 2 transistors ,2 resistors and 1 diode inside ,only three pins ,base emitter and collector are coming out.Rest are connected internally.So its quite OK to assume each of them as transistor for ease.

Use a well regulated and filtered power supply.

Connect a 10K POT in series with the input as volume control if you need.Not shown in circuit diagram.

All electrolytic capacitors must be rated at least 50volts.

Power supply for this circuit.

A +40/-40 unregulated dual supply for powering this amplifier project is shown below. This power supply is only enough for powering one channel and for stereo applications double the current ratings of the transformer, diodes and fuses.

1. 2 X 60 Watts Stereo Amplifier Circuit – is designed using LM4780, an audio amplifier IC that can deliver 60 Watt RMS output power per channel to 8 Ohms speakers. Advantages of using this IC are low harmonic distortion compared to other IC amplifiers of similar category and a power supply rejection rate of 85db. In addition it require minimum components and a built in mute function.

2. Headphone Amplifier Circuit – This is a simple circuit which uses only 3 transistors, that can be used to drive your headphone. It can be easily built by any one and can be powered using a 3 volts battery.

3. Mosfet Amplifier Circuit – This circuit is designed using two Mosfet’s and one transistor; which makes it an easy to build circuit. It can deliver 18 Watts output power to 8 ohms speaker or 30 watts to 4 ohms speaker; you can do it the way you like it. Another advantage of this circuit is the minimal use of components.

4. 40 Watts Amplifier using TDA1514 – TDA1514 is a high performance hi – fi amplifier from Philips. It requires a dual +25/-25 volts supply. Advantages of using TDA1514 are low THD, mute standby feature, thermal protection and other features. It can deliver 40 watts of output power to an 8 ohm speaker. You need a proper heat sink for the desired reliability of this circuit.

5. 2 X 32 Watts Stereo Amplifier Circuit – This circuit is built using TDA2050 which is a 32 Watts Class AB Audio amplifier IC (monolithic) . This IC has many features like thermal shut down, low THD, short circuit protection etc. This circuit uses Two of these IC TDA205o; one for each channel. An 18 volts dual power supply is required to power this circuit.

Comments

Hello sir. I need your help because i have a problem with the output sound. when the volume level is max the output sound will distort or noise. my transformer is 15 0 15 6ampere. i Hope for your reply sir

Hello Sir,
With pleasure may I tell that the circuit diagram of 150 watt amplifier is very good to read. The “Stereo Amp” will be identical with “Mono Amp” circuit. Anyway before the assembling, powering and connecting the exact specified load to the system,the sound quality will tell me pleasant and nice. Sir instead of publishing only the circuit diagram,kindly provide the stereo amplifier PCB, the power supply board along with the transformer specifications say the data for winding with gauge of the insulated copper wire for primary number of turns as well as for secondary reminding of ampere, the core size and lamination’s brand etc. Sir I am very much interested in assembling of stereo sound systems with high output in RMS ratio. If you provide me here above items,very frankly indicate, I don”t mind about the cost at all.

I am not real knowledgeable on SS…I do have an Ampeg B3158 bass guitar combo. This amp uses TIP 142 and 147’s in it’s power output circuit.
My question is can these pwr transistors develop lower output volume but still function or they like a diode….it works or doesn’t?
I ask because when I first got the amp I didn’t have to turn the gain and master up as much as I do lately.
Just curious and thanks for your time to whoever replies to straighten me out on this……
Ron Thomas
OKC

Sir I have made that circuit on vero board.All continuity and connections are double checked found OK.But when I give signal input from PC or mobile no audio output is available at speaker.Please help me and guide me sir what should I do.Im using 24-0-24 Transformer and instead to Diodes Bridge combination I am using a Packed Bridge rectifier.Dc out put is ±30.Please please please help me and guide me sir.

This circuit doesn’t work properly…. It has a lot of distortion in output further more the output sound is not more than 10 watt rms…
Noise is removed by replacing 220ohms resistor with 550 ohms resistor. It will adjust the gain of amplifier so noise will be removed.

Is it advantageous to use a constant current source instead of R6? The aim is to emulate an infinite impedance theoretically increasing the common mode rejection ratio to infinity?

To avoid using positive feedback in the output stage is it beneficial to add two more transistors connected in such a way that the Darlington’s would be made of three cascaded transistors instead of the usual two.

I did some reseach and what I learnt so far corroborates my impression that this circuit is well designed and worthy of a try.

I am interested in building this amplifier but am finding difficulty accepting the differential input should be driven between -45V and +45V. I also think, using PNP transistors for a differential input is quite uncommon today.

1) To meet my criteria I changed parts of the circuit so that the differential input is made of NPN transistors instead that are connected between 0V (common, ground) and the +45V.
2) The output stage has also been modified so that R3 and R5 are on the negative side of the supply (-45V). I moved the driver transistor Q3 to the other side, that is, the +45V making sure to keep the same resistor values. Naturally, Q3 has been replaced by a PNP transistor.
3) In the input stage, differential input, the signal ground has been made the same as that of the differential input stage.

Sir,
I have the amplifier board using transistors TIP143andTIP147 by using
transformer is 28-0-28,10A dual power supply.My problem is switch on the power supply ,I heard the sound on the speaker is like feedback between the mic and speaker….woooooooo….so you help to rectify the problem

i finished this amplifier and the sound seems very clear but very low comparing to a 100w …i get like 8 or 10w at max ….for a speaker of 80w 8ohm i used a supply of +-45 5A and 2 of 0.22ohms 5w and a pairs of MN2488 MP1620 instead of the tip142/147 and for the rest i used the same as the shema and no picofards for modifications … any suggestions plizzz ?

Hey guys have you already tried the PCB design of this schematic by jspayne? but there are just some modifications recommended to improve the amplifier’s performance, i think it is good. you can search it in google.

Dear Seetharaman Sir
If i use 2SD2390/ 2SB1560 can i power this from 56-0-56V and what will be the output power? Using TIP142/ TIP147 and power it from 56-0-56V all of the sudden the emitter and collector of output transistor got shorted.

can i power this 150w amplifier from a 25-0-25 transformer.how much watts will be the output if i charge it from 25-0-25 8ohm speaker.
please find the link below, will it works and give 400w output.which is the better circuit 150w circuit in this page or the circuit in the link bellow.please help me to choose one.

am working presently on this amplifier.. But i couldnt get tip147 could u pls tell me which i can use as a replacemant, and also the 30 0 30v transformer is expensive here, is there anyway i can use the cheaper one… And again the 10k potientiometer how do i connect it to the circuit

You must replace bc558 transistors before using this supply. Because! Maximum voltage that bc558 can bear is 60v so search for high voltage transistors in place of bc558…. Hope this solved your quest… ☺

Hi sir,
I did this amp perfectly and also done 100w sub amp. Iam a +2 student.IAM Living in a villege In my area, fm signals not clear. Sir please suggest me a good fm anteena booster ckt. Please help me sir. Thanks

100% working Stereo complete PCB layout of this amplifier including power supply on the single board is available along with all the building instructions and online skype support only for 5 US dollars.
Visit our link
facebook.com/auxticshttp://www.it-tronics.blogspot.com

Hello Guys , i have a complete PCB layout as well as circuit diagram of this great circuit in stereo form along with the power supply on the single PCB board.
If any one is interested then feel free to contact me

Sir i again try it. But a proble is that, After 5 minute when play music the power transistors are damageing. I dont know what is the actual problem. I am using 27 0 27 volt 5 amp (+-35volt) transformer and 8ohm woofr. I also check the diodes it is working perfect. I use a wire loop between the base of 2 power transisters but no responce. I think that it is the problem of voltge. Please help me sir…….

Now cold check all components check the wiring thoroughly. Check your heat sink size. By shorting output transistor base is not having any response your driver transistor may be defective. Add 100PF ceramic disc capacitor between collector and base of Q3. Check whether the supply leads are quite short and decoupled properly.

Sir i did this amp for stereo application 1 month ago. Its working fine. I made another one for my subwoofer it worked . But one problem, when i play music it condinue less than one minute then the power transistors are blooming very hot and a loud noise producing . I dont know what happent. Iam using 35volt 5amp dual supply and 10″ 8ohm jbl subwoofr. Please help me siq,

Hello..I have plans to build a good sub-woofer. Can I use the same circuit for the same? Can some one point me to the PCB, sub-woofer box measurements? I believe now a days SMPS power supply’s available, can SMPS supply used to power this amp? Any guidance will be greatly appreciated. BTW, I am from Bangalore, anyone know what is the best place to buy these components?

sir I want to add a filter circuit to this amplifier which requires a separate power supply of +12 / -12 VDC at 3 amp, can you give me a power supply circuit that can supply +/- 12 VDC and +/- 35 VDC from a single transformer
thanks

Sir i did this. But when i connect supply a noise is producing like “buuuu”. I think that my circut is perfect becouse i chek it somany times using the diagram. I dont know what happent. I use +/-32volt 5amp dual power supply and 4ohm 10inch speker and 0.5 ohm 10w instad of 0.33. When i connect supply, tip142 , 147 and 0.5ohm 10w become very hot. Now i waste somuch money to build this amp. I dont know what happent? I think that it is problem of tip transistors. Please give me a suggestion to overcome this sir, please……..

I rebuilt the circuit on a breadboard with tip142, tip41c and four quarter watt 3K3 for a one-watt configuration. I test it with two computer power supplies (+12, 0, -12). TIP41C (no heat sink attached) feels cold, TIP142 and TIP147 along with the two 0.33 ohm 7 W resistors are HOT. The speaker goes half way to the negative direction and stays there with no sound coming out. Where should I check for pre-amplified signal and where should I check for drive signal from TIP41C ?

PS: The PSUs are not exactly 12 volts unloaded, one is ~10.5 v and the other is ~11.3 v, both can supply 8 amperes safely on the 12 v rail. I have a (+45, 0, -45) unregulated power-supply, should I test with it or solve the issue at 12 V first ?

HELLO THERE , I AM BACK,LET ME HELP YOU ,FIRST OF ALL THE ABOVE CIRCUIT DIAGRAM IS COMPLETELY TESTED AND RELIABLE FOR TROUBLE FREE SOUND PLEASE CONSTRUCT EXACT CIRCUIT AS GIVEN,AND
1.SUPPLY SHOULD BE +/-40-0-40 TO +/-45-0-45 VOLTS WEATHER REGULATED OR UNREGULATED. THE CARE SHOULD BE TAKEN THAT IT SHOULD NOT EXEED 45 VOLTS,FOR BETTER RESULTS THE SUPPLY SHOULD BE BETWEEN +/-40 TO +/-45 VOLTS
2. SPEAKERS SHOULD BE GOOD QUALITY AT LEAST 12″ 100-150WATT HANDLING CAPACITY
3.USE LARGE HEATSINKS FOR TIP142AND TIP147 ATLEAST 4*6INCHES AND FOR TIP41C USE 3*3INCHES OR CLASSIC HEATSINK OF 12″*4 INCHES
4.AND USE 680PF 100 VOLTS ON POWER TRANSISTORS BASE TO COLLECTOR.
NOW IT GIVES YOU STABLE AMP
BYE……….

Hi,i am a Ryan, i have gone through this article here,what i wanna know is you said here, ” SPEAKERS SHOULD BE GOOD QUALITY AT LEAST 12″ 100-150WATT HANDLING CAPACITY” but i wanna know what should be the Impedance? 8ohms 150w or 4ohms 150w? I have a BPL cwx 59 model which has a Amp section made of TDA 2050 & i am gonna upgrade that for my mixing purpose,for the Lower end 20Hz-100Hz. I am geting confused as the pre amp has a section of 5band +/- 10db Graphic eq of 100,400,1k,4k & 12khz also with a bass boost,so if i boost the 100Hz with the Bass boost ‘ON’ that point of time the Speaker need a more wattage as well as the Amp…so what would be the proper wattage of the Speaker to use i am getting confused. Hence A little help would be appricated.

The two questions are :
1> 8 Ohms 150w Or 4ohms 150(If 8 Ohms150,i’ll use 4Ohms 300w)
2> If i boost 100Hzs 10 db that raises all the frequencies 100 below,now with that if i make bass boost on (which is boosting from inbetween 70-80Hz & below, so what would be the wattage of the speaker?

hello ryan
actually this amp delivers actual wattage of 150watts on 4ohms speakers, and 100 watts on 8 ohms.
TDA2050 IS 30 WATT IC,SO THE SPEAKER WILL NOT WORK.
USE GOOD QUALITY SPEAKERS ,YOU ASKED ABOUT FREQUENCY ,IT DOES NOT MATTERS JUST FIX IT UP ON ANY AUDIBLE POINT , I HVE USED THIS CIRCUIT IN 2006,SINCE THAN IT IS WORKING AMAZINGLY.I HAVE USED 30.0.30/ 10AMP TRANSFORMER FOR SUPPLY FOR 150+150 WATT.
NOTE: THOSE PEOPLE WHO DO NOT HAVE HEAVY WATT SPEAKERS USE LOW CURRENT SUPPLY ,BUT THE VOLTAGE SHOULD BE SAME. YOU CAN USE 30.0.30/5 AMP SUPPLY FOR BOTH THE CHANNELS, IT WILL PROVDE YOU THE SAME QUALITY SOUND ,BUT THE WATTAGE WILL BE HALF NEARLY 80+80 WATTS.

Sir, I built the circuit but I’m having problems, C2, C3 and R2 blowed up twice. I checked the traces for shorts but I found none. All capacitors are rated 50 V, R2 is rated 1/4 W. I’m using a 45 V dual supply. The TIP141 gets warm, TIP41C reflects wind like sound in the speaker, TIP147 is cool and on power up, the speaker cone moves forward and keeps it’s position until power is removed. Please help !

Check TIP147 collector-emitter must have become dead short check all your wiring and polarity of capacitors, if they are interchanged( plus- minus polarity of the capacitor) it becomes a link wire instead of an DC isolator. A thorough check is required including D1 & D2.

Sir please give me a solution to solve ma problem. I have +/-40v 5amp supply. I made this amp. I using 4ohm subwofr. How can do to connect my woofr on my amp to get good perfomence. Is there any circut for connecting 4ohm load into 8ohm amp to get good perfomance? Please help….

sir I made d modification u told me i.e. Adding a diode n a 22/27 ohms in series with d two present diodes but am still having d crossover distortion.so I want to set the standing current but I don’t knw how to do dat (Whr to place the red and the probes)to carry out d reading and setting of the q-current. pls help me out sir.thanks

You can measure the milli volt drop across R8 and set it for say you are using 0.47 ohms then 0.47 * 0.06A = 30 to 40 milli volt and set for this value. If you cannot measure milli volt accurately. Use current measurement in the collector circuit of Q1. Break collector of Q1 to positive supply line and insert an ammeter and set the current for 50 to 80 mA.

Being a TO220 casing transistor it may get heated up and may blow. Use only TIP142 for better thermal stability as it has a better casing TO247. You may have to reduce the power output to <100watts with TIP131.

HELLO THERE, FOR BEST RESULT FROM THIS AMPLIFIER USE:
1: 40-0-40 VOLTS TO 42-0-42 VOLTS 8 AMPERE DC POWER SUPPLY,THAN USE 12″ 4-8 OHM SPEAKER POWER HANDLING UPTO 150WATTS.
2:IF YOU ARE USING 40-0-40 VOLTS TO 42-0-42 VOLTS 5 AMPERE DC POWER SUPPLY FOR BOTH THE CHANNELS THAN USE 12″ 4-8 OHM SPEAKER POWER HANDLING UPTO 100-150 WATTS.
3: use 0.5ohm resister ,in place of 0.33ohm and add 680pf in tip142/147
FOR STABLE OUTPUT
4: HEAT SINK SHOULD BE PROPER,I HAVE USED 3″*3″HEAT SINK WITH FINS/OR BAR FOR TIP41,AND 4″*6″* WITH FINS FOR TIP 142,TIP 147.
5: YOU CAN USE CLASSIC HEAT SINK OF 12″ WHICH IS USED FOR 2N3055 TRANSISTORS
I AM USING 2*12″ WOOFER ,AND TWEETERS OF 4OHM LOAD WITH +-42V 10 AMPERE SUPPLY & use 0.5ohm resister ,in place of 0.33ohm and add 680pf in tip142/147
FOR STABLE OUTPUT
and the amp is running good trouble free since 1999

seetharaman sir i have made one circuit of 120+120 watt from efy book of 1986 circuit used TR 2N 6261,AND 2N6254,THIS CIRCUIT GIVES THE BEST SOUND I HAVE THAT CIRCUIT ALSO AND THIS DELIVER GOOD HIGH GOOD MID AND GOOD LOW,AND I MUST SAY 2ND BEST AMP I HAVE EVER MADE IN MY LIFE , AND SIR WHEN YOU COMPARE THIS 120WATT CIRCUIT IT BEATS THE TIP 142 CIRCUIT OF 150+150WATT CIRCUIT I HAVE ALSO COMPARED AND MOST OF MY FRIEND WHO USE TO MAKE CIRCUIT THEY ALSO DID THIS,AND SOME PROFESSIONAL LIKE NB BROS,(NAKRA BROS) CP DELHI GAVE ME THE SAME COMPLIMENT SOME SOME YEARS BACK BUT NOW A DAYS WE DO NOT HAVE THESE 2 TRANSISTORS
I CAN USE 2N3773 =IN PLACE OF 2N6254,
BUT I DO NOT KNOW THE REPLACEMENT OF 2N6261 WHICH IS EASILY AVAILABLE IN INDIA

seetharaman sir,i have three amp i am using in this time as you said this TIP142/147, CIRCUIT IS same and modified version of philips circuit 1972, but believe me sir the low is very good in bd182 circuit in compare to this 150 watt circuit,am currently using it,
sir i have also observe that using 2N3773 TR,is gives more loud and low frequency in compare to 2SC5200 TR,,I tried many circuit.
so please suggest me ,even your subwoofer circuit made by 2n3773 is gives good low freq.

hello sir ,i made the jspyne circuit same as shown on site but it decreases the sound output.but your circuit has no problem iam using it since 2009 and believe me it is giving sound trouble free on 45-0-45,10ampre supply and 150watt load of speaker

Hello sir, I can’t seem to find the 0.33 ohm resistor in my country due to it’s high power rating and I don’t wany to order it online as it would be too costly, can I ommit it or replace it by a self made wire wound which I won’t know it’s power rating, or can you suggest other solutions ? Thank you in advance, regards, Youssef Aly.

IF YOU ALL BUDDIES COMP[ARE THIS CIRCUIT WITH JS PYNE THAN,THIS CIRCUIT SCORE 100/100,AND JS PYNE MODEL 40/100,SO BE CARE FULL sir ,SITHARAMAN IS VERY GOOD AND KNOWLEDGEABLE PERSON IN ELECTRONICS ,I HAVE SEEN MANY CIRCUIT MADE BY THEM WHICH ARE GOOD AND WITH GOOD EXPLANATION,,
I

hello all i made this circuit in year 2009, and in first attempt ,the output is good ,but ihave seen the problem is of low frequency,this circuit delvers good output and good mid,and high frequency,but when we talk about low frequency,than it is not good ,i am using sub woofer also but there is no good punch,
and jspyne circuit cuts the output from the original one so do not try that i tried it 4 times with 1% resistors,and caltron cap,but no use ,jspyne circuit reduce the output upto 50%,than there is no use,so please you people do not waste time
I have used 45-0-45 volts 10ampre supply

1.i have made many circuits from net,from efy and other books i have tried 47 diff.circuits but i have seen only one good circuit which is made by philips company based on the book of M.D HULL,THIS delvers 25/40 watt RMS output by 0-60volts, TR BD139,140 AND BD 182,and delever you good sound even you do not have good speakers .
2. I am not criticizing anybody’s creativity but TRUTH IS THIS ONLY ,so please help me out ,if you have good circuit

Hello that is the same circuit of Philips (from Philips 1972 Audio Application Book)I modified and used it in my Motional Feed Back Amplifier. In fact I have used 2 amplifiers in bridged mode to get around 150 watts into 8 ohms speaker.
In the revision 2 of JSpyne the gain feed back circuit was changed to reduce the amplifier gain to R4 / R2 22K / 1K only 22 hence you require higher drive, comparing to original circuit. You can improve the gain by reducing R2 to 220 ohms. a gain of 100. 5 times better. It is customary to keep the gain around 50 in the output amplifier (for better frequency bandwidth)and increase the input through pre-amplifier to achieve the same output.

Hi
It is my plan to try to build this amplifier, however I have got some questions that I hope you answer:
1. The specification says 150W in 4 ohm, do you know how much it will deliver in to a 8 ohm load?
2. What size heatsink would you recommend?
3. The transistors TIP 142 / Tip 147, would you recommend them in TO-247 or TO-220 housing?

I made this circut. It worked perfectly. After on day i use it for my home audio systen but one problem a deep noise is producing this ckt and 0.33ohm resistor heating very much . I give +/-35v 5amp power suply and 10inch 4ohm woofer. I dont know what happent? Please give me a solution sir… And i have one more qustion can i use 0.2 ohm instead of 0.33 ohm? I hope ur replay… Thankx…

Use 0.47 ohms 5 watts in place of 0.33 ohms do not use a lower value. May be for interconnection you have not used proper screened cable. If you have a layout problem connect a low pass filter of 1K ohms resistance vs 470 pf in the input of the amplifier. connect also a 100pf capacitor between collector and base of Q3. refer (http://pcb.jspayne.com/150wattamp.html)

hi sir!! finally i found the solution for stereo from single transformer,
(the problem is tip 41 is linked with heat-sink now i disconnect the link the problem is solved. now it works fine thanks a lot.!!

Hello Sir
sir I made this circuit first on bread board and it was working perfectly. but after 1 week when i made this again with new components this cicuit not working. . sir plz help me what should I do, i have to submit this project on tommorrow. . |
kindly suggest me.
Thank u

sir I can’t figure out wats wrong with my amp after building it I tought it will work fine,but instead I’m only having a very little sound @ d output . pls help me sir. D one I made the first time worked fine. N I couldn’t get 3.3k @ 1watt so I used a 2.7k n a 750ohms resistors in series. Wen I read d value across d two resistor with my dmm it showed me 3.35k pls sir suggest me on wat to do.could it b dat my resistor combination led to d@ problem?

Mostly transistors might have blown. Use cold check with a multimeter to find out damaged components. check the wiring and component values and polarity of each component used. use 33 ohms 10 watts resistance in positive and negative supply rail before switching on again after thoroughly inspecting the assembly again. If any one of 33 ohms smokes switch off immediately and look for the mistakes and correct it. Still if you cannot solve the problem kindly contact a local friend who is well versed in assembling high power amplifiers to help you. If this is the first time you are assembling a high power amplifier it is better take an advice from a local professional in assembling and proceed.

Looks like a poor quality transformer with bad regulation A 5amp transformer of 30-0-30 cannot give plus minus 60 volts it can give only plus minus 45 volts at the maximum. Kindly use series regulators and reduce the voltage to around plus minus 40 and use. for 60 volt plus minus this amplifier will get burnt you may have to replace all the semiconductors and capacitors with higher voltage rating, which are very expensive.

Sir i use +/-35v dual power supplay and 10 inch 4ohm load. I made the pcb layout of this amp using the link you are posted on the site (http://pcb.jspayne.com/150wattamp.html)
please solve my problem sir,

Place a wire link between Q1 and Q2 base and energize and see if not getting heated up. It looks there is a problem in 1N4007 diodes. If it is still getting heated up check TIP147 for collector emitter short. Are using 18 SWG or better DC power connecting cables and are they less than 2inches. While switching what sound you are getting from speakers.

Sir, i have one problem on my ckt. When give supplay to my circut a loud noise producing. I dont get 0.33 ohm 7watt. But i got 0.33ohm 2watt. I use 2 nos of 0.33ohm 2watt in series and connect parallel with another 2nos of0.33ohm 2watt in series. Tip 142 is heating very much and 0.33ohm resistor in tip142 is heating very much. Tip 147 is not heating. I dont know what is the actual reason of this. Please help me sir to overcome this . I hopeing ur comment. Please

May be D1 & D2 are wired other way round that is anode/cathode inter changed. Check collector emitter and base of TIP142 & 147 for correctness. Check the healthiness of TIP147. How much DC you are feeding to amplifier. What is the speaker impedance. What about the input to the amplifier whether connected to ground or left open. Have you taken care of short length of DC power supply cable should be less than 2 inches. Check all the wiring and your layout and DC supply do not exceed plus minus 35 volts DC. Please give more details to give a solution.

Sir,the transformer shown in the power supply has a 30-0-30 output,can you explain how it get increased to 40-0-40 V at o/p after filtering.
I am building a 5.1 amp,i have a 30V 6A single supply transformer for powering the 5 channels(2xTDA 2050+3xTDA 2030),after filtering the tranformer with a 4700mf capacitor how much voltage l get as o/p…??
,i am thinking to add 100W amp(mensioned in this site)for sub woofer,is this configuration is correct…..i’m a beginner .i really liked this site..frgve for my bad eng…..waiting for your replay…

If you use 320 volt RMS AC voltage transformer the DC output will be peak of RMS voltage after rectifying and filtering. THAT is 30 X 1.414 = 42 volt s DC. you will get +42 0 -42 volts DC. you will get 42 volts TDA2030 will get damaged it requires a maximum of 36 volts for 4 ohms load speaker. use only 24 volts transformer. for TDA2050 it is ok as 44volt dc is max allowed.

i m also want to build 5.1 using this circuit. i build stereo but this is not successful for stereo………….. but for mono this gives very good output.
if u find any solution for 5.1 plz share here..thank you!!!

Hi John this is a good stereo amplifier provided the layout is taken care by using thick cable for DC power supply and one point earthing and screen not connected at both ends etc. this project is not just for a beginner. High power amplifier are a bit difficult to assemble. this can be used or sub woofer amplifier and you can use TDA 2030 or 2050 for the surround front left, right and center speakers. This way you can achieve a nice 5.1 ssystem

sir thanks again for another reply!! i build this darlington for left right. And for subwoofer i use TDA7294 ic (100watts rms). and i use stk 4141 for center and rears. But there is a problem with this left right channels. both channels inputs are comes out through both left and right channels. this is only my problem. i use unregulated +44/-44 and GND power supply for all these amps from single transformer.is this problem? i think this is the problem. thanks again!!

you can use the standard 0.47 or 0.5 ohms 10 watts which are available readily in the market.
If space is not at premium in your amplifier enclosure you can use 2nos 0.33 ohms 2 watt in series and connect in parallel with another 2nos 0.33 ohms in series to achieve 0.33 ohms 8 watts finally. Choice is yours.

Yes you can use 6A5 it is 6Amps 500v PIV rectifier.
Please use any circuit which uses dual supply(both plus and minus voltage with zero volt reference)To get +12 volt use 7812 12 volt 3 pin regulator ic, for positive supply and to get -12volt use a 7912, a 3pin negative voltage regulator ic.

Sir i want to builda a subwofr filter using my +35/-35v 5amp dual power supplay . I saw a filter circut on this site using +12/-12 dual power supply. Please give me a solution to convert 35v to 12v. Iam waiting for ur replay. Please sir ..

AND i use this as subwoofer amp. gives GOOD output .
.
BUT i m sorry to say this. THE output of stk 4141 for subwoofer is better this one.(for best effect i use the power capacitors value is 10000/50v*2 for dual)
OTHER than subwoofer amp. . this darlington are rocks (better use for left right)

finaly i use split and pin protect ciruit power supply as you given the link. now i use single tranformer for two(stereo) channells. it works good. …………
BUT. . . . one major problem that is the input of both chanells are amplifying through both channells. . that mean the input of 1st channel is amplifying through both channel. . AND also 2nd channell input also amplifying through both channels. . BUT no dissorted audio. CLEAR output. PLZ give some solutions for this . . THANK you sir!!

i use independent circuit of output transistor pin short protection for each channels. and also completely i trace out the circuit for any mistakes. there is nothing to problem. except the ground(0volt) is common.i think this is the problem. because both speakers are looped with common ground volt. this may short with the other end of the output of each channels. but i cant understand this problem.bcoz of my poor knowledge.
FINALLY I REALIZE THAT THERE IS NO WAY FOR STEREO FROM ONE TRANSFORMER.
SEPARATE TRANSFORMER IS THE ONLY RIGHT SOLUTION.

You have to use 25 – 0 – 25 volt @ 5 AmpAC transformer with bridge rectifier and filter capacitors to get both +ve and -ve power supply required for the amplifier. please refer to the power supply circuit given in 100watts sub woofer amplifier.

plz help sir! i finished one channel. it works perfectly. but i made another channel for stereo. here the problem that the first channel input amplifying through both channels. and the second channel input is dead.(no audio) and also the heat is abnormal. what is the solution for this problem.plz help.

If you are using single power supply for both the channels disconnect first good amplifier connect the one getting heated up by putting a link between Q1 and Q2 base the current through output transistors should fall and the if audio input is supplied it should sound distorted. If it is not achievable check the complete wiring and for a defective component, isolate replace and rectify.

i use dual power supply. i found the problem with power supply. that is i gave the supply for both channels from one tranformer.(this is the problem) AND i need solution for power supply for 5.1 using this circuits from only one transformer(sec=24-0-24). IS THIS POSSIBLE ??. If it is possible i m very lucky. THANK you for your response sir.

Ensure all improvements are carried out as per following sitehttp://pcb.jspayne.com/150wattamp.html
Ensure each amplifier circuit is isolated by a diode and 1000uF in parallel with 0.1uF ceramic disc capacitor for both positive and negative supply.

i finished this circuit it runs smoothly and there is no abnormal heat, wow!! great sound ………… its enough for an home!! before making this..i asked an shopper about 150 watt 5.1 amp. they says 3500 rupees for 6 channels. but this cost just 200 rupees per channel with big heat sink. so i m happily says “thank you admin”. now i m going to make 5.1 using this circuit

Good evening Sir can you please help me!I m new in electronics I can’t find tip142, tip147, tip41 Can I use other power transistor instead of these tips I like to making electronic kit. And I also want a perfect amp circuit diagram in one channel with parts list include watt which produce 200watt with deep bass. I m waiting for your answer. Thank in advance.

sir I have finished assembling dis circuit and d sound is quite good bt d only problem am facing nw is one of d output transistor heating up (2sb1560) but d oder transistor (2sd2390) heat is normal.pls sir how can I fix dis problem? am using bc557 at d amplified stage

dear sir seetharaman, I am new to electronic n I have so much interest in building dis circuit.pls sir I need ur assistance.Whr I am I couldn’t find bc558 and tip147. Pls sir I need to knw wat other transistors can I u instead? I will b waiting ur reply sir. Thanks

Hi… Seetharaman sir i have question for you sir..
i have designed this amplifier in stereo and using dual transformers 25-0-25 for each channel and using a stereo pre amplifier ( bass treble kit) .. All is ok the amplifier is working perfectly and giving me a pure 150 watts output i think more than 150 watts because its running my 4 12 inch speakers very smoothly…
I am facing a problem when the amplifier’s sound is low then it does not give a clear output it gives me a distorted output and when i increase the problem it gets fine…
i need to know that what is the problem exactly ?

Sir how can test the Tip142 and 147 to know if it is dead. My first circuit worked perfectly and what if the fuse is removed, will cause the transistors to over heat. This circuit im doing now is mine. But the other one i did i sold out. Please i need ur reply as soon as possible my father is on my neck. Thanks alot. I will be waiting. Or send it to my Email address (princestechnology@gmail.com)

By deleting fuse your protection to the amplifier is lost in the event of speaker leads are (amplifier output) shorted both the output darlington transistors will blow off. You can test the transistor with a multimeter in diode test mode. being darlington transistor forward continuity of base emitter junction will be 1.2V and Base collector will be 0.6. collector emitter in reverse bias will be 0.6 due to built in protection diode (see internal details shown above)and forward continuity will be open circuit.

Hi Andrew go to the following site modifications indicated to be implemented for stable reception.http://pcb.jspayne.com/150wattamp.html first circuit is good enough. if you have layout problems then use second circuit.

Sir,
To enhance output can I use BDW83C & BDW84C in lieu of TIP 147/TIP142 or any other MOSFET? Kindly suggest. After changing Transistor how should I combine two sets (left & Right Channel) of amplifier to produce enhanced output. Kindly draw a diagram. How much supply DC votls and Amperes need for Single pair and combined pair?

I have a couple of 32-0-32 volts @ 4Amp and 40-0-40 volts @ 5Amp trafos lying around at home.

So I thought of building an amp which can use them. Any schematics for something like this? I haven’t searched on the net, maybe there are some amps out there. In terms of audio quality, the most important thing is CLEAN and BALANCED sound. We need to hear the little things!

I was thinking to build a set of mono block amplifiers, not too fancy but nice enough for my Dynaudio Audience 42W speakers. Can someone help me point out some amplifier designs? Think I can handle a build completely from scratch.
So what is a wise decision? I estimate, with these supplies you should get around 150 watts.

Im not sure whats wrong with my circut because if i mesure the pins where is speaker output i got 37V,and tip41c get really hot but the other two are cold (Im testing without speaker and MP3 only power supply). I hope you could help me with solving the problem. Thank you.

I would like to drive an 11 ohm speaker from this 150 watt amplifier. I only require a 105 watt output. Using TIP142GOSND and TIP147GOSND both rated for 100v@10amps, I estimate the supply would require around +/- 90vdc. The circuit appears to be able to handle the load if I use all components rated for the increase supply voltage. Do you recommend and changes to the original design? or have any suggestions to drive the 11 ohm load?

We have built this circuit about more than 1000 times this works well and perfect..
If you are facing any type of problems regarding this circuit then you can contact us any time….. we are here for your assistance
We have a complete tutorial ( images as well as videos ) of this circuit’s building procedure…
If you are realy willing to built this circuit with perfection then contact us below given mail…. we are here to solve your problems… thanks , have a good dayengr.omer9@gmail.com

someone help me with this, i used a scopemeter(CRO) to monitor the progress of the input signal from the signal generator into the amplifier and at the emiter of Q5 there was less amplitude than from the base and and moving forward it was becoming less and less please i need to know was it because of the lower voltage (-+22.5) i used or there could be some other problem please could it be darlington transistors thanks

hi seetharman, i switched on the power supply and the tip 142 heated up very first and eventually the volume of the speaker deminished,the tip 142 cooled and i again switched on the power supply but there was no heat as if the tip 142 was dead. even there was no sign of heating in tip 41 and tip 147 are they dead.i also want to know how i can get some results of the amplifier using the signal generator and the CRO coz i tried and there was no change in the output from the CRO with respect to the input signal ie there was no amplification effect, how can i get this.

i used the lower voltage because some of my components were at first blowing and burning with higher voltage but i think i can now increaase the voltage thanks to mr seetharman for your wonderfull work

Hi mr seetharman thanks alot for guiding me up to this point the circuit is working but i used +/-22.5V to power the amplifier and the output was low,i also noticed that the TIPs are not heating as expected,i used a DVD as my audio input. so my question is, could it be the low voltage that i used or my TIPs are dead? the speaker is 150watts 5ohms.

nice amp works great…i assembled 8amps with this circuit good high freq. and low frequency response using jrc 4558 ic as tone control..i used it for lead guitar, bass guitar & keyboard…i even use tip41/tip42 & tip2955/tip3055 as darlington pair as output x’sistor with supply voltage of +/-40vdc @6amperes…using dual voice coil speaker @ 450watts 4ohms…heat is minimal low noise no hum…

This circuit works, but D1 & D2, which are supposed to provide the bias for the “A” part of the class AB description, can come from anywhere and therefore have unpredictable actual forward voltages. Garden variety 1N4007 diodes can have forward voltages ranging from 0.3V to 1V! The lower this voltage gets may result in audible crossover distortion, and the higher it is, Q1 and Q2 may conduct heavily (more A than B, at all times including no-signal conditions), become very hot and die if not properly heatsinked! It would probably matter little if this was a lower-power amplifier (<40W), but for a design that aspires to 150W, a transistor in place of D1 and D2 whose base is connected to a pot that can fine tune the bias voltage is essential, IMHO (the www is filled w circuits for this).

well, i used a heat sink for TIP142, but wasn’t that big and i also placed a fun beside it which reduced the temperature to some extent, but the sound still distorts and diminishes eventually. when this happens, i turn it off for it to cool. when turn it on it takes a longer time for it to sound and the sound is even very low and noisy.i will have to turn it off and wait for a very long time, even though the tip142 is cool before it sounds. it doesn’t end there, it still over heats and the same thing happens again……Anyway,tip 147 doesn’t heat at all. it remains cold while tip 142 becomes hot. i don’t know if there is something wrong. it looks like all the work is on tip142. I will get a bigger heat sink to try and see the results.

okay, thank u very much. but then i want to know, tip142 and tip 147 are darlington pair transistors with side base, but i do a diode-test of these transistors, they read as side base and they can also read as if they are center base. is that the nature of these transistors? that is how they were when i bought them from the market.

hi seetharman i used +-22.5V to power the amplifier and every connections seemed to be ok but when i connected to the signal generator for the input signal,the output from the CRO(CATHOD RAY OSCELOSCOP)was smaller than the input meaning there was deamplification instead.please i need also to know into details how the preamplifier and darlington pair works on my email ,could it be yhe lower voltage i used please coment.thanks regards.

Hi Mr. Seetharaman, the amplifier is now working, but tip 142 becomes very hot when i power it, and the sound eventually becomes noisy and finally diminish.in any case i am using c558 instead of bc558. i don’t know if it is going to be a problem.

Hi mr seetharman my capacitor C2 10mf 100V blew of when i powered it but before blowing it was not allowing the signal input to flow untill i had to shotit,please could there be any problem with this capacitor or could it be some where else, coment (these are the changes i made, i replaced 0.33ohms with 0.47ohms 5W and i used 120pf capacitor instead of 100pf and two 15-0-15 3A TRANSFORMER in series insted of 30-0-30 5A)the way you wrote to me and my power supply was +46/-46V.

hi mr seetharman, i powered my amplifier with -46/+46 volts power supply that i made using the 2 15-0-15 3A transformer and the 220 ohms resister got burnt so i am asking my self could it be that the resistance was too small or the watage i used and i have bought half watts instead of quarter watts please coment on this. i also want to use the signal generator and the CRO to determine some x-tics of this amplifier.please coment on this.

thank u very much for the reply.i have done the modification and it can now pick the sound of the mp3 at a lower volume. but it gives a hazy sound with background noise “puf…puf” with breakage in the sound what can i do to get a clear sound?

thank you very much.but my problem is;
-i have built the amp and it is working, but the sound is very bad. i also have to open my mp3 player to the maximum volume before the sound becomes stable, which is even a bad sound. what can i do about it?
-also, the voltage specification of the capacitors. whenever i go to buy the components, i am challenged with the voltage, since one capacitance value can have different voltages. are there any means of detecting the voltage required?

Hi Daniel check with no signal input to amplifier check the current drawn by the output darling-ton pair (by measuring their collector current) It should be between 50 to 60mA if not adjust by adding a resistance of 10 to 27 ohms and a diode IN4007 in series with D1 and D2 once this current is achieved it should work nicely.
Refer modified drawing in the following linkhttp://pcb.jspayne.com/150wattamp.html

Thanks mr seetharman for your advice and am doing it but i need image of the pcb connection of both the power supply and the amplifier on my email if possible the videos of the connection.please sir i need this because i want to avoid loss of some components due to connection mistakes because we have very limited components in the market.

Hi Moses use the full winding without center tap of 15-0-15 3amps transformer. It will be 30 Volts. Use one more transformer in the same way in series ensure it gives 60 volts end to end if not interchange one of the transformers secondary winding connection. it will be 60 volts end to end. and use the inter connection between transformer as center tap. Now your power supply of 180 watts is ready. this can easily power your amplifier one channel. do the same for other channel also.

Hi mr seetharman i have almost made all my connections but my main problem is the transformer. we only have 15-0-15 3A transformer in the market please advise me about this,i also need the pcb connections in my email(alelem@rocketmail.com) may be if possible the videos.thanks

I am looking at this circuit and cannot understand how 2 X 1n4007 diodes are able to bias the output transistors (darlingtons) into conduction, surely you would need at leat 4 diodes, to bias the 4 Vbe junctions? Yet many have built it and say it works well, what am I missing?

Hi connecting two transformers in series will increase the voltage but the current will be the same, if they are identical transformers. this is the basic. Please conduct the experiments and give a feed back by using different complex combination of transformers. please check your mail.

thanks mr seetharman for u reply but there is one thing confUsing me about the transformer coz last time u told me to use 2nos 15-0-15 3A transformer and connect in series and it will give 30-0-30 6A my question is what about the TIP 142 AND 147 transistors which requires maximum current of 5A, WONT THEY OVER HEAT WHEN I USE THOSE TRANSFORMERS IN SERIES SINCE THEY WILL PRODUCE 6A.

Thanks alot Mr seetharman for your reply coz you have given me another hope of coming out with what the project requires and i think i need to know how you are coming out with some of this calculations of like the output power, input signal and the output voltage of the power supply.may be on my email;alelem@rocketmail.com, good day sir.

sir, i was able to get 0.47 5W resistor that you told me about except that i couldnt find the 15-0-15 5A transformer and am going to use 15-0-15 3A TRANSFORMER and i will try to measure the output voltage.what do you suggest about the fuse coz am still using the 5A fuse and am going to use the 6A10 diodes in the bridge but am not going to change other components in the power supply appart from what i have stated above.i hope i shall go to the amplifier after the power supply.thanks alot mr seetharman for your wonderfull work i have already learnt alot even before finishing the project.meet tomorrow.

Hi Moses you can use 2nos 15-0-15 3amp transformer in series to get 30-0-30 6 amps. with the above power supply and 4 ohms speaker you will get 150 watts output with 8 ohms speaker around 100 watts out put power with an input of 300 milli volt rms signal.

i have failed to get 15-0-15 5A TRANSFORMER and am thinking of using 15-0-15 3A transformer. in this case what will be the output in volts of the power supply, what about the output of the amplifier in watts,and what will be the magnitude of the audio input.please we have only 3A transformer and less in the electronics shops of our city and thats why i have choosen now 15-0-15 3A transformer thanks, your reply will be appreciated

Thanks alot mr seetharman.i tried looking for the 15-0-15 5A transformer but i didnt find it in the all of our city but instead i found 15-10-15 3A transformer and our laboratory technician advised me to use it and determine what it will give at the output of the power supply and my question is what will be the output voltage of the power supply if i use 15-0-15 3A TRANSFORMER, what will be the output of the amplifier,and what should be the magnitude of the audio input,will there be any adjustment in the other components like the bridge rectifier and other components in the amplifier.thanks your respond will be appreciated sir and i hope i will learn alot from this project.

am going to look for 15-0-15 5A transformer but can i use 6A10 diodes in the rectifier circuit instead of 6A5 thanks.what other alternatives are there for 0.33 ohms 7W resistor coz i dont have them in our electronics shops.

Hi Moses 6A5 is 6Amps 500Volt PIV rectifier. 6A10 is 6Amps 1000Volt PIV rectifier. you can use. In place of 0.33 ohms you can use 0.47 or 0.5 ohms 5watt if both are not available use two nos 1 ohm 2 watt in parallel. you please send me your mail to seethasub@hotmail.com

thanks alot mr seetharman for your wonderful work i want to use acombined bass cut and treble out filter please advise me about the connections and if possible send me the details on my email including how to connect it and the circuit including my new circuit and again am having problem of getting a transformer for the power supply am in uganda and today i checked all the electronics shops in our city but i didnt get transformer 30-0-30 5A, i got only maximum of 18-0-18 3A i didnt get 0.33ohms resistior for amplifier but all other components were there except diodes for the power supply instead a got 6A10 and i wanted to use it instead.please advise me about the possible adjustments and if possible the circuit diagram on my email coz i dont want to give up for this amplifier.i also have a maximum of 12-0-12volts power supply in our laboratory and i prefered it instead of assembliong anew power supply please advise me about the possible adjustment for this power supply and the circuit diagram of the adjustment.thanks

HELLO SIR,
MY DVD PLAYER HAS SUBWOOFER OUTPUT, SO IS A SUBWOOFER FILTER NECESSARY?
OR MAY I USE A BASS KIT AFTER SUBWOOFER OUT PUT AND BEFORE INPUT TO THIS AMPLIFIER. AND FROM WHERE I CAN PURCHASE THIS PCB? CAN U PROVIDE ME THIS PCB? THANKS